My research to date has focused on adult well-being in cohabiting unions. The proposed project will allow me to expand my research agenda to investigate the family processes and qualities of cohabiting families and their implications for child and adolescent well-being. Demographers have been slow to integrate these elements in their analyses of individual well-being, focusing instead on larger structural factors. Nevertheless, the demographic and developmental perspectives actually are complementary as together they emphasize the individual, process, and contextual qualities of the family environment, all of which shape children's well-being. I will consider the significance of the family environment at the person, process, and context levels (including parental psychological well-being, parenting behaviors, parent-child relationship quality, economic resources, and family instability) for the development of youth in cohabiting families, paying special attention to the complications presented by poverty and minority status. I will use data from the 1992-2002 Survey of Program Dynamics and the three waves of the National Longitudinal Study of Adolescent Health to examine the influence of family processes and qualities on five core domains of children's development: (1) physical, (2) psychological and emotional, (3) social, (4) cognitive and educational, and (5) economic well-being. Both of these data sets permit me to account for prior living arrangement transitions as well as duration in the current family form. Econometric techniques will be use to account for selection effects. I will also conduct in-depth interviews with cohabiting parents to expand on the results I obtain from the SPD and Add Health. This strategy will allow me to explore in greater detail the factors that are most strongly linked to child well-being and identify other key aspects of the family environment that were not examined in the secondary data analyses. The K-01 award will provide me with strong mentorship and specialized training in child and adolescent development as well as econometrics and qualitative methods, which will enable me to expand my demographic research on cohabitation and well-being. By incorporating a developmental perspective, I will be better equipped to address how and why newly emerging family structures such as cohabitation influence children's lives.